Telecommunications apparatus and methods

ABSTRACT

A method of operating a terminal device to communicate with a network infrastructure equipment in a wireless telecommunications system using radio resources comprising a narrowband carrier supported within a wider system frequency bandwidth of the wireless telecommunications system, wherein the method comprises: establishing initial frequencies for radio resources comprising the narrowband carrier; receiving configuration signalling from the network infrastructure equipment providing an indication of a frequency shift to apply to the initial frequencies for the radio resources comprising the narrowband carrier; establishing shifted frequencies for the radio resources comprising the narrowband carrier by applying the indicated frequency shift to the initial frequencies; and communicating with the network infrastructure equipment using the radio resources for the narrowband carrier with the shifted frequencies

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/969,990, filed Aug. 14, 2020, which is based on PCT filingPCT/EP2019/053688, filed Feb. 14, 2019, which claims priority to EP18157251.2, filed Feb. 16, 2018, the entire contents of each areincorporated herein by reference.

BACKGROUND Field

The present disclosure relates to telecommunications apparatus andmethods.

Description of Related Art

The “background” description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description which may nototherwise qualify as prior art at the time of filing, are neitherexpressly or impliedly admitted as prior art against the presentinvention.

Recent generation mobile telecommunication systems, such as those basedon the 3GPP defined UMTS and Long Term Evolution (LTE) architectures,are able to support a wider range of services than simple voice andmessaging services offered by previous generations of mobiletelecommunication systems. For example, with the improved radiointerface and enhanced data rates provided by LTE systems, a user isable to enjoy high data-rate applications such as mobile video streamingand mobile video conferencing that would previously only have beenavailable via a fixed line data connection. In addition to supportingthese kinds of more sophisticated services and devices, it is alsoproposed for newer generation mobile telecommunication systems tosupport less complex services and devices which make use of the reliableand wide ranging coverage of newer generation mobile telecommunicationsystems without necessarily needing to rely on the high data ratesavailable in such systems.

Future wireless communications networks will therefore be expected toroutinely and efficiently support communications with a wider range ofdevices associated with a wider range of data traffic profiles and typesthan current systems are optimised to support. For example it isexpected future wireless communications networks will be expected toefficiently support communications with devices including reducedcomplexity devices, machine type communication (MTC) devices, highresolution video displays, virtual reality headsets and so on. Some ofthese different types of devices may be deployed in very large numbers,for example low complexity devices for supporting the “Internet ofThings”, and may typically be associated with the transmission ofrelatively small amounts of data with relatively high latency tolerance.

In view of this there is expected to be a desire for future wirelesscommunications networks, for example those which may be referred to as5G or new radio (NR) system/new radio access technology (RAT) systems,as well as future iterations/releases of existing systems, toefficiently support connectivity for a wide range of devices associatedwith different applications and different characteristic data trafficprofiles.

One example area of current interest in this regard includes theso-called “Internet of Things”, or IoT for short. The 3GPP has proposedin Release 13 of the 3GPP specifications to develop technologies forsupporting narrowband (NB)-IoT and so-called enhanced MTC (eMTC)operation using an LTE/4G wireless access interface and wirelessinfrastructure. More recently there have been proposals to build onthese ideas in Release 14 of the 3GPP specifications with so-calledenhanced NB-IoT (eNB-IoT) and further enhanced MTC (feMTC), and inRelease 15 of the 3GPP specifications with so-called further enhancedNB-IoT (feNB-IoT) and even further enhanced MTC (efeMTC). See, forexample, [1], [2], [3], [4]. At least some devices making use of thesetechnologies are expected to be low complexity and inexpensive devicesrequiring relatively infrequent communication of relatively lowbandwidth data, and as such may be configured to operate on a restricted(narrower) baseband bandwidth as compared to other terminal devicesoperating in a network.

The increasing use of different types of terminal devices associatedwith different operating bandwidths gives rise to new challenges forefficiently handling communications in wireless telecommunicationssystems that need to be addressed.

SUMMARY

Respective aspects and features of the present disclosure are defined inthe appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, but are notrestrictive, of the present technology. The described embodiments,together with further advantages, will be best understood by referenceto the following detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings wherein likereference numerals designate identical or corresponding parts throughoutthe several views, and wherein:

FIG. 1 schematically represents some aspects of an LTE-type wirelesstelecommunication system which may be configured to operate inaccordance with certain embodiments of the present disclosure;

FIG. 2 schematically represents an arrangement of physical resourceblocks (PRBs) that span a system bandwidth (BW) to support twonarrowband (NB) carriers in a wireless telecommunication system;

FIG. 3 schematically represents an arrangement of PRBs that span asystem BW and which are grouped into physical resource block groups(RBGs) in a wireless telecommunication system;

FIG. 4 schematically represents an arrangement of PRBs spanning a systemBW and which are grouped into RBGs and which support a plurality of NBcarriers in a wireless telecommunication system;

FIG. 5 schematically represents an arrangement of PRBs spanning a systemBW and which are grouped into RBGs and which support a plurality of NBcarriers in a wireless telecommunication system with one of the NBcarriers being scheduled for use;

FIG. 6 schematically represents some aspects of a wirelesstelecommunication system in accordance with certain embodiments of thepresent disclosure;

FIGS. 7 to 10 schematically represents arrangements of PRBs spanning asystem BW and which are grouped into RBGs and which support a pluralityof NB carriers in a wireless telecommunication system which are shiftedin frequency relative to their predefined (unshifted) frequencies inaccordance with certain embodiments of the present disclosure;

FIG. 11 is a flow chart schematically representing some operatingaspects of a base station (network infrastructure equipment) inaccordance with certain embodiments of the disclosure; and

FIG. 12 is a flow chart schematically representing some operatingaspects of a terminal device (UE) in accordance with certain embodimentsof the disclosure.

DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 provides a schematic diagram illustrating some basicfunctionality of a mobile telecommunications network/system 100operating generally in accordance with LTE principles, but which mayalso support other radio access technologies, and which may be adaptedto implement embodiments of the disclosure as described herein. Variouselements of FIG. 1 and certain aspects of their respective modes ofoperation are well-known and defined in the relevant standardsadministered by the 3GPP (RTM) body, and also described in many books onthe subject, for example, Holma H. and Toskala A [5]. It will beappreciated that operational aspects of the telecommunications networksdiscussed herein which are not specifically described (for example inrelation to specific communication protocols and physical channels forcommunicating between different elements) may be implemented inaccordance with any known techniques, for example according to therelevant standards and known proposed modifications and additions to therelevant standards.

The network 100 includes a plurality of base stations 101 connected to acore network 102. Each base station provides a coverage area 103 (i.e. acell) within which data can be communicated to and from terminal devices104. Data is transmitted from base stations 101 to terminal devices 104within their respective coverage areas 103 via a radio downlink (DL).Data is transmitted from terminal devices 104 to the base stations 101via a radio uplink (UL). The core network 102 routes data to and fromthe terminal devices 104 via the respective base stations 101 andprovides functions such as authentication, mobility management, chargingand so on. Terminal devices may also be referred to as mobile stations,user equipment (UE), user terminals, mobile radios, communicationsdevices, and so forth. Base stations, which are an example of networkinfrastructure equipment/network access nodes, may also be referred toas transceiver stations/nodeBs/e-nodeBs, g-nodeBs and so forth. In thisregard different terminology is often associated with differentgenerations of wireless telecommunications systems for elementsproviding broadly comparable functionality. However, certain embodimentsof the disclosure may be equally implemented in different generations ofwireless telecommunications systems, and for simplicity certainterminology may be used regardless of the underlying networkarchitecture. That is to say, the use of a specific term in relation tocertain example implementations is not intended to indicate theseimplementations are limited to a certain generation of network that maybe most associated with that particular terminology.

While certain embodiments may be generally described herein in relationto the network architecture represented in FIG. 1 , it will beappreciated corresponding approaches may equally be adopted in networksconforming to other overall configurations, for example configurationsassociated with proposed approaches for new radio access technology(RAT), NR, wireless mobile telecommunications networks/systems. A newRAT network may comprise communication cells that each comprise acontrolling node in communication with a core network component and aplurality of distributed units (radio access nodes/remote transmissionand reception points (TRPs)) within the cell. The distributed units maybe responsible for providing the radio access interface for terminaldevices connected to the NR network. Each distributed unit has acoverage area (radio access footprint) which together with each otherdefine the coverage of the communication cell. Each distributed unitincludes transceiver circuitry for transmission and reception ofwireless signals and processor circuitry configured to control therespective distributed units. In terms of broad top-level functionality,the core network component of such a new RAT telecommunications systemmay be broadly considered to correspond with the core network 102represented in FIG. 1 , and the respective controlling nodes and theirassociated distributed units/TRPs may be broadly considered to providefunctionality corresponding to the base stations of FIG. 1 . Thus, theterm network infrastructure equipment/access node may be used toencompass these elements and more conventional base-station typeelements of wireless telecommunications systems. Depending on theapplication at hand the responsibility for scheduling transmissionswhich are scheduled on the radio interface between the respectivedistributed units and the terminal devices may lie with the controllingnode/centralised unit and/or the distributed units/TRPs. A terminaldevice operating in this proposed new RAT architecture may thus exchangesignalling with a first controlling node via one or more of thedistributed units associated with the controlling node. In someimplementations the involvement of the distributed units in routingcommunications from the terminal device to a controlling node(controlling unit) may be transparent to the terminal device. It willfurther be appreciated this example represents merely one example of aproposed architecture for a new RAT telecommunications system in whichapproaches in accordance with the principles described herein may beadopted, and the functionality disclosed herein may also be applied inrespect of wireless telecommunications systems having differentarchitectures.

Thus certain embodiments of the disclosure as discussed herein may beimplemented in wireless telecommunication systems/networks according tovarious different architectures, such as the example architecture shownin FIG. 1 . It will be appreciated the specific wirelesstelecommunications architecture in any given implementation is not ofprimary significance to the principles described herein. In this regard,certain embodiments of the disclosure may be described generally in thecontext of communications between network infrastructureequipment/access nodes and a terminal device, wherein the specificnature of the network infrastructure equipment/access node and theterminal device will depend on the network infrastructure for theimplementation at hand. For example, in some scenarios the networkinfrastructure equipment/access node may comprise a base station, suchas an LTE-type base station 101 as shown in FIG. 1 which is adapted toprovide functionality in accordance with the principles describedherein, and in other examples the network infrastructure equipment maycomprise a control unit/controlling node and/or a TRP in a new RATarchitecture of the kind discussed above.

In wireless telecommunications networks, such as LTE type networks,there are different Radio Resource Control (RRC) modes for terminaldevices. For example, it is common to support an RRC idle mode(RRC_IDLE) and an RRC connected mode (RRC_CONNECTED), and other RRCmodes/states may also be supported. A terminal device in the idle modemay move to connected mode, for example because it needs to transmituplink data or respond to a paging request, by undertaking a randomaccess procedure, and a terminal device in the connected mode may moveto the idle mode, for example because it has finished a current exchangeof higher layer user plane data with the network, by undertaking an RRCconnection release procedure. Radio Resource Control signalling issignalling exchanged between a terminal device and a network in supportof the different RRC modes to control how radio resources areused/managed in the network. Examples of RRC signalling includesignalling associated with RRC connection establishment and releasefunctions, broadcast of system information (e.g. system informationblocks, SIBs), radio bearer establishment, reconfiguration and release,RRC connection mobility procedures, paging notification and release andouter loop power control. In general, RRC signalling may be consideredto be signalling/messages between network infrastructure equipment(eNB/base station) and terminal devices (UE) at Layer 3 (radio linkcontrol layer) in the radio network protocol stack. Typically RRCsignalling is used for configuration for operations of features in a UEwhich are semi-static (i.e. the configuration will be used until anotherRRC message updates the configuration). RRC signalling can becommunicated/broadcast in system information, e.g. SIB in an LTEcontext, or may be UE specific.

As noted above, it is proposed for wireless telecommunications systemsto support some terminal devices, for example, Internet of Things (IoT)type terminal devices and Machine Type Communications devices (MTC) on anarrowband carrier operating within a wider system (host) frequencybandwidth. A terminal device configured to operate using a restrictedsubset of radio resources (narrowband carrier) spanning a host frequencybandwidth (host carrier) in this way may, for convenience ofterminology, sometimes be referred to herein as a narrowband (NB)terminal device while a terminal device able to operate using the fullhost frequency bandwidth may, for convenience of terminology, sometimesbe referred to herein as a legacy or non-narrowband terminal device. Inthis regard it will be appreciated the term “legacy” is used here simplyto help distinguish between narrowband and non-narrowband terminaldevices. The term is not to be interpreted as indicating such terminaldevices are in any way outdated, but merely to indicate that they areconfigured to operate over the full operating bandwidth of the wirelesstelecommunications system in the usual/conventional way rather thanbeing configured to operate within a restricted narrowband within thefull operating bandwidth of the wireless telecommunications system.

Wireless telecommunications systems may have a range of different systembandwidths. For example, in an LTE context a system may have an overalloperating bandwidth (system BW) of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHzor 20 MHz. Radio resources are divided in frequency into subcarriers(which in LTE have a 15 kHz channel spacing) with 12 subcarrierscorresponding to a physical resource block, PRB (in LTE a PRB has a timeduration of 0.5 ms (half a subframe)). In the frequency domain/dimensionthe number of PRBs for a carrier depends on the system bandwidth asindicated in the first and second columns in Table 1.

TABLE 1 System System Bandwidth Bandwidth Number of 1.4 MHz RBG size(MHz) (PRBs) Narrowband carriers (NRB) 1.4 MHz 6 1 1 3 MHz 15 2 2 5 MHz25 4 2 10 MHz 50 8 3 15 MHz 75 12 4 20 MHz 100 16 4

One approach for narrowband/small bandwidth operation in an LTE contextis to use narrowbands with a bandwidth of 6 PRBs (i.e. 6×12=72subcarriers) corresponding to a 1.4 MHz carrier (72 subcarriers with a15 kHz spacing corresponds to 1.08 MHz but additional bandwidth is usedfor filtering, signal roll-off, etc.). Because the narrowband carrierbandwidth for an NB terminal device (1.4 MHz) is smaller than themaximum carrier bandwidth that a legacy terminal device must support (20MHz in LTE), the NB terminal device can use a less complex transceiver(RF front end), which can help reduce manufacturing costs and powerconsumption during use. A system bandwidth may be wide enough to supportmultiple non-overlapping narrowband carriers at different frequencylocations across the system bandwidth. For example, in an LTE context,all but the smallest system bandwidth (1.4 MHz) has the potential tosupport more than one 6 PRB wide narrowband. The potential number ofdifferent narrowbands for each system bandwidth in LTE is indicated inthe third column in Table 1. The frequency locations for the narrowbandswithin a system frequency bandwidth may be fixed (e.g. predefined by anoperating standard for the wireless telecommunications system).

In the general case the number of PRBs in a system bandwidth will not bean integer multiple of the number of PRBs in a narrowband. For example,with the exception of the smallest 1.4 MHz system bandwidth in LTE,dividing the total number of PRBs in the system bandwidth (second columnin Table 1) into the number of potential narrowbands that can besupported (second column in Table 1) leaves some PRBs remaining (whichmay be referred to here as remaining PRBs). As noted above, thefrequency locations for the narrowbands within a system frequencybandwidth may be predefined, and in an LTE context this is done in sucha way that the narrowband locations and the remaining PRBs are botharranged symmetrically about the centre of the system bandwidth. For LTEthe remaining PRBs are distributed such that if there is an even numberof remaining PRBs they are located in equal numbers at the upper andlower ends of the system bandwidth. If there is an odd number ofremaining PRBs, one is located at the centre of the system frequencybandwidth and any others are located in equal numbers at the upper andlower ends of the system bandwidth. The narrowbands are arrangedcontiguously between the remaining PRBs.

FIG. 2 schematically shows narrowband and remaining PRB locationsarranged according to these principles for the example of a 3 MHz/15 PRBsystem bandwidth (System BW). Thus FIG. 2 schematically shows the 15PRBs (labelled PRB #00, PRB #01, . . . , PRB #14) arranged in frequencyfrom a lower end of the system bandwidth to an upper end of the systembandwidth (left to right in the figure). The 15 PRBs can support two 6PRB narrowbands, labelled NB #0 and NB #1 in FIG. 2 , with 3 PRBsremaining. The PRBs allocated to support narrowband operation are shownwith no shading while the remaining PRBs (i.e. PRBs not allocated tosupport narrowband operation for this particular arrangement) are shownwith shading. It will be appreciated that references herein to certainPRBs supporting narrowband operation are intended to mean these are thePRBs that may be used to support narrowband operation if desired, and atother times they may be used to support legacy/non-narrowband operation.That is to say the PRBs shown in the figures as being associated withnarrowband operation indicate the potential narrowband locationssupported within the system bandwidth. Whether any particular narrowbandis active/scheduled for use at any given time (i.e. the correspondingPRBs are used for narrowband operation) or not currently active (i.e.the corresponding PRBs are free to be used for non-narrowband/legacyoperation) may be determined in accordance with the general establishedprinciples for scheduling (i.e. allocating resources to) narrowbandoperation in a wireless telecommunications system.

Thus for the arrangement of FIG. 2 there are three remaining PRBs (i.e.PRBs not used to support any narrowband), and so one is located in themiddle of the system frequency band (PRB #07) and one is located at eachend of the system frequency band (PRB #00 and PRB #14). A firstnarrowband, NB #0, is formed using {PRB #01, PRB #02, PRB #03, PRB #04,PRB #05, PRB #06} and a second narrowband, NB #1, is formed using {PRB#08, PRB #09, PRB #10, PRB #11, PRB #12, PRB #13}.

It is common for PRBs in wireless telecommunications system to bedivided into a plurality of predefined groups of physical resourceblocks (i.e. resource block groups, RBGs) which are scheduled together.For example, in LTE, the resource allocation on the physical downlinkshared channel (PDSCH) typically uses what is known as ResourceAllocation Type 0. For this the system bandwidth is divided intoResource Block Groups (RBGs) consisting of N_(RB) PRBs (if the number ofPRBs for the system bandwidth is not an integer multiple of N_(RB) theleftover PRBs may form a final RBG with fewer than N_(RB) PRBs). An RBGis the granularity of resource allocation for PDSCH (i.e. the smallestallocation that can be made), i.e. the downlink resources are allocatedin numbers of RBGs for the terminal device. This restriction helpsprovide a balance between scheduling flexibility and control signallingoverhead. For LTE the value N_(RB) is dependent upon the systembandwidth and is indicated in the fourth column in Table 1.

FIG. 3 schematically shows a known arrangement of RBGs for the exampleof an LTE 10 MHz/50 PRB system bandwidth (System BW). Thus FIG. 3schematically shows the 50 PRBs (labelled PRB #00, PRB #01, . . . , PRB#49) arranged in frequency from a lower end of the system bandwidth toan upper end of the system bandwidth (left to right in the figure). Asindicated in Table 1, for this system bandwidth the RBG size N_(RB) is 3PRB so the 50 PRBs can support sixteen 3-PRB RBGs (labelled RBG #00, RBG#01, . . . , RBG #15) and one 2 PRB RBG (labelled RBG #16), i.e. a totalof 17 RBG.

FIG. 4 is similar to, and will be understood from FIG. 3 , but inaddition to showing how the system bandwidth BW (again 10 MHz for thisexample) is divided into 50 physical resource blocks (PRB #00, PRB #01,. . . , PRB #49) which are grouped into 17 resource block groups (RBG#00, RBG #01, . . . , RBG #16), FIG. 4 also schematically shows thepredefined locations for the eight 6 PRB wide narrowbands supported forthis system bandwidth in LTE in accordance with the principles set outabove for locating narrowbands. Thus, the eight narrowbands (labelledNarrowband #00, Narrowband #01, . . . , Narrowband #07) are contiguouslyarranged in frequency with Narrowband #00 on physical resource blocksPRB #01 to PRB #06, Narrowband #01 on physical resource blocks PRB #07to PRB #12, and so on up to Narrowband #07 on physical resource blocksPRB #43 to PRB #48. There are two remaining physical resource blocks,namely PRB #00 and PRB #49, that are not allocated to support any of thenarrowbands and these are located at the end of the frequency bandwidthBW.

For the arrangement represented in FIG. 4 , which is in accordance withthe currently proposed approaches for LTE, it has been observed that thenarrowbands, NBs, and resource block groups, RBGs, are not well alignedin frequency [6], i.e. the narrowbands and RBG do not start or end withthe same PRB. A consequence of this nonalignment of the boundaries forthe narrowbands with boundaries for the resource block groups is areduced capacity for the system as a whole, which can be seen from FIG.5 .

FIG. 5 is similar to, and will be understood from FIG. 4 and again showshow a 10 MHz LTE system bandwidth BW is divided into 50 physicalresource blocks (PRB #00, PRB #01, . . . , PRB #49) which are groupedinto 17 resource block groups (RBG #00, RBG #01, . . . , RBG #16) andalso how the predefined locations for the 8 narrowbands (Narrowband #00,Narrowband #01, . . . , Narrowband #07) supported for this systembandwidth in LTE are arranged in frequency. FIG. 5 further represents aspecific operating scenario in which one of the narrowbands (in thisexample Narrowband #03 on PRB #19 to PRB #24) is scheduled for use—i.e.the radio resources PRB #19 to PRB #24 are currently in use to supportNB operation, but the other radio resources (PRB #00 to PRB #18 and PRB#25 to PRB #49) are not currently needed to support NB operation. Ofcourse it will be appreciated this is simply one example implementationscenario, in other scenarios different narrowbands may be currentlyscheduled/active according to traffic needs as determined in accordancewith the conventional approaches for scheduling in wirelesstelecommunications systems supporting narrowband operation.

As can be seen in FIG. 5 , the scheduled narrowband (Narrowband #03) ison physical resource blocks (PRB #19 to PRB #24) which are spread acrossthree resource block groups (RBG #06 to RBG #08). The RBGs which are notused to support the scheduled narrowband (i.e. RBG #00 to RBG #05 andRBG #09 to RBG #16), or any other currently scheduled narrowband(s), canbe used to support other communications in the system, e.g. forcommunicating with legacy/non-narrowband terminal devices (assumingthese RBGs are not being used to support other currently-schedulednarrowband(s)). However, because of the miss-alignment in the NB and RBGboundaries there are some PRBs which are not used for supporting thescheduled narrowband but which nonetheless cannot be used to supportlegacy operation because they are in an RBG containing PRBs which areneeded to support the scheduled NB, remembering the legacy operation canonly schedule resources at the granularity of an RBG. Thus, for theimplementation example represented in FIG. 5 the radio resourcescomprising PRB #18, PRB #25 and PRB #26 are in effect blocked for use bylegacy terminal devices. This leads to a degradation in the cell'sthroughput/spectral efficiency.

The inventors have recognised that shifting the narrowband locationsrelative to the RBG boundaries can help to mitigate this issue byreducing the number of RBGs that include PRBs used to support individualnarrowbands. Also, the inventors have recognised that redefining thefixed narrowband locations would potentially cause misalignment withnarrowband locations for older narrowband terminal devices operatingaccording to previous releases of narrowband-capable terminal devicestandards (i.e. Rel-13 and Rel-14 in an LTE context), and so asemi-static or dynamic approach in shifting the narrowbands would givethe flexibility to the network to manage these resources. For example ifthere are not many legacy (LTE) UEs then there is no need to shift anynarrowbands.

Thus in accordance with certain embodiments of the disclosure it isproposed to retain predefined locations (i.e. what might be referred toas initial locations/initial frequencies for radio resources comprisingthe narrowband carriers) for narrowband carriers but to provide aprocedure for moving/shifting the predefined locations to new locations(i.e. to provide what might be referred to as shifted frequencies forthe radio resources comprising the narrowband carriers). Thus asemi-static or dynamic approach to shifting the narrowbands can be usedto provide flexibility in a network for managing these resources. Forexample, in accordance with some approaches an indication of a shift toapply to a predefined/initial set of frequencies for a narrowbandcarrier may be signalled from a base station (network entity) to aterminal device, for example in RRC signalling as system information ina system information block, SIB, or UE (terminal device) specificsignalling to indicate frequency shift(s) for the narrowband(s), whichmay sometimes be referred to herein as a shift pattern. The shiftpattern may thus inform the UE of the number of PRBs for which to shiftthe narrowband(s).

FIG. 6 schematically shows a telecommunications system 500 according toan embodiment of the present disclosure. The telecommunications system500 in this example is based broadly around an LTE-type architecture. Assuch many aspects of the operation of the telecommunicationssystem/network 500 are known and understood and are not described herein detail in the interest of brevity. Operational aspects of thetelecommunications system 500 which are not specifically describedherein may be implemented in accordance with any known techniques, forexample according to the current LTE-standards.

The telecommunications system 500 comprises a core network part (evolvedpacket core) 502 coupled to a radio network part. The radio network partcomprises a base station (evolved-nodeB) 504 coupled to a plurality ofterminal devices. In this example, two terminal devices are shown,namely a first terminal device 506 and a second terminal device 508. Itwill of course be appreciated that in practice the radio network partmay comprise a plurality of base stations serving a larger number ofterminal devices across various communication cells. However, only asingle base station and two terminal devices are shown in FIG. 6 in theinterests of simplicity.

As with a conventional mobile radio network, the terminal devices 506,508 are arranged to communicate data to and from the base station(transceiver station) 504. The base station is in turn communicativelyconnected to a serving gateway, S-GW, (not shown) in the core networkpart which is arranged to perform routing and management of mobilecommunications services to the terminal devices in thetelecommunications system 500 via the base station 504. In order tomaintain mobility management and connectivity, the core network part 502also includes a mobility management entity (not shown) which manages theenhanced packet service (EPS) connections with the terminal devices 506,508 operating in the communications system based on subscriberinformation stored in a home subscriber server (HSS). Other networkcomponents in the core network (also not shown for simplicity) include apolicy charging and resource function (PCRF) and a packet data networkgateway (PDN-GW) which provides a connection from the core network part502 to an external packet data network, for example the Internet. Asnoted above, the operation of the various elements of the communicationssystem 500 shown in FIG. 6 may be broadly conventional apart from wheremodified to provide functionality in accordance with embodiments of thepresent disclosure as discussed herein.

In this example, it is assumed the first terminal device 506 is aconventional smartphone-type terminal device communicating with the basestation 504 in a conventional manner (i.e. the first terminal device isa legacy terminal device that does not rely on using narrowbands). Itwill be appreciated the first terminal device need not be asmartphone-type terminal device and could equally be another type oflegacy terminal device, including a device that has the capability tosupport narrowband operation, but is currently not doing so. Theconventional/legacy terminal device 506 comprises transceiver circuitry506 a (which may also be referred to as a transceiver/transceiver unit)for transmission and reception of wireless signals and processorcircuitry 506 b (which may also be referred to as a processor/processorunit) configured to control the device 506. The processor circuitry 506b may comprise various sub-units/sub-circuits for providingfunctionality as explained further herein. These sub-units may beimplemented as discrete hardware elements or as appropriately configuredfunctions of the processor circuitry. Thus the processor circuitry 506 bmay comprise circuitry which is suitably configured/programmed toprovide the desired functionality using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The transceiver circuitry 506 a and theprocessor circuitry 506 b are schematically shown in FIG. 6 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these circuitry elements can be provided invarious different ways, for example using one or more suitablyprogrammed programmable computer(s), or one or more suitably configuredapplication-specific integrated circuit(s)/circuitry/chip(s)/chipset(s).As will be appreciated the legacy (non-narrowband) terminal device 506will in general comprise various other elements associated with itsoperating functionality.

In this example, it is assumed the second terminal device 508 is amachine-type communication (MTC) terminal device 508 adapted to operateon a narrowband/restricted bandwidth (i.e. the second terminal devicemay be referred to as a narrowband terminal device/UE). However, it willbe appreciated this represents merely one specific implementation ofapproaches in accordance with embodiments of the disclosure, and inother cases, the same principles may be applied in respect of terminaldevices that support narrowband operation but which are not reducedcapability MTC terminal devices, but may, for example, comprisesmartphone terminal devices, or indeed any other form of terminaldevice, that may be operating in a wireless telecommunications systemand which is configured to support narrowband operation (i.e. configuredto communicate using only a restricted subset of the radio resourcesspanning the system frequency bandwidth). In this regard it will beappreciated that a narrowband terminal device may in some cases be ableto be reconfigured to function as a non-narrowband/legacy terminaldevice.

The narrowband terminal device 508 comprises transceiver circuitry 508 a(which may also be referred to as a transceiver/transceiver unit) fortransmission and reception of wireless signals and processor circuitry508 b (which may also be referred to as a processor/processor unit)configured to control the terminal device 508. The processor circuitry508 b may comprise various sub-units/sub-circuits for providing desiredfunctionality as explained further herein. These sub-units may beimplemented as discrete hardware elements or as appropriately configuredfunctions of the processor circuitry. Thus the processor circuitry 508 bmay comprise circuitry which is suitably configured/programmed toprovide the desired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The transceiver circuitry 508 a and theprocessor circuitry 508 b are schematically shown in FIG. 6 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these circuitry elements can be provided invarious different ways, for example using one or more suitablyprogrammed programmable computer(s), or one or more suitably configuredapplication-specific integrated circuit(s)/circuitry/chip(s)/chipset(s).It will be appreciated the terminal device 508 will in general comprisevarious other elements associated with its operating functionality, forexample a power source, user interface, and so forth, but these are notshown in FIG. 6 in the interests of simplicity.

The base station 504 comprises transceiver circuitry 504 a (which mayalso be referred to as a transceiver/transceiver unit) for transmissionand reception of wireless signals and processor circuitry 504 b (whichmay also be referred to as a processor/processor unit) configured tocontrol the base station 504 to operate in accordance with embodimentsof the present disclosure as described herein. The processor circuitry504 b may comprise various sub-units/sub-circuits for providing desiredfunctionality as explained further herein. These sub-units may beimplemented as discrete hardware elements or as appropriately configuredfunctions of the processor circuitry. Thus the processor circuitry 504 bmay comprise circuitry which is suitably configured/programmed toprovide the desired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The transceiver circuitry 504 a and theprocessor circuitry 504 b are schematically shown in FIG. 6 as separateelements for ease of representation. However, it will be appreciatedthat the functionality of these circuitry elements can be provided invarious different ways, for example using one or more suitablyprogrammed programmable computer(s), or one or more suitably configuredapplication-specific integrated circuit(s)/circuitry/chip(s)/chipset(s).It will be appreciated the base station 504 will in general comprisevarious other elements associated with its operating functionality.

Thus, the base station 504 is configured to communicate data with boththe legacy terminal device 506 and the narrowband terminal device 508according to an embodiment of the disclosure over respectivecommunication links 510, 512. The base station 504 is configured tocommunicate with the legacy terminal device 506 over the associatedradio communication link 510 and with the narrowband UE 508 over theassociated radio communication link 512 generally following theestablished principles of LTE-based communications, apart from usingmodified procedures for configuring the frequency location for thenarrowband communications over the radio communication link 512 betweenthe base station and the narrowband UE 508 in accordance with certainembodiments of the present disclosure as described herein.

As noted above, in accordance with certain embodiments of the disclosureit is proposed to retain predefined locations for radio resourcescomprising one or more narrowband carriers and to provide a procedurefor selectively moving/shifting the predefined locations in frequency,for example using RRC signalling/signals.

Thus, approaches in accordance with certain embodiments of thedisclosure may involve methods of operating a terminal device and anetwork infrastructure equipment to communicate using a narrowbandcarrier supported within a wider system frequency bandwidth of awireless telecommunications system. The terminal device and networkinfrastructure equipment establish initial frequencies for radioresources comprising a narrowband carrier. These may be established, forexample, through being defined in an operating standard for the wirelesstelecommunications system, or in some cases the network infrastructureequipment may be configured to flexibly select the initial frequencylocation (i.e. initial frequencies for radio resources comprising thenarrowband) for a narrowband and communicate an indication of this tothe terminal device. Subsequently, when the network infrastructureequipment determines a need to configure the narrowband for use by theterminal device it establishes shifted frequencies for the radioresources comprising the narrowband carrier obtained by selecting afrequency shift to apply to the initial frequencies. The base stationmay be configured to do this in such a way as to (PRB) align the shiftednarrowband location with resource block groups within the systembandwidth so that the narrowband impacts fewer resource block groupswhen located on the shifted frequencies as compared to when located onthe initial (non-shifted) frequencies so as to help overcome the issueof blocked physical resource blocks discussed above. It will beappreciated the specific reason why the network infrastructure equipmentdetermines a need to communicate with the terminal device using thenarrowband and the information content of the communications on thenarrowband are not significant to the principles discussed herein. Thenetwork infrastructure equipment then transmits configuration signallingto the terminal device to provide an indication of the frequency shift,e.g. using RRC signalling. The terminal device then establishes theshifted frequencies for the radio resources comprising the narrowbandcarrier by applying the indicated frequency shift to the initialfrequencies. Thus, at this stage the terminal device and the networkinfrastructure equipment have both established the shifted frequencylocation and can proceed to communicate with each other using the radioresources for the narrowband carrier on the shifted frequencies.

In some examples the indication of the frequency shift may indicate anumber of PRBs that should be shifted that applies for all narrowbandsin the same direction. An example of this is shown in FIG. 7 .

FIG. 7 is similar to, and will be understood from FIG. 5 and again showsa 10 MHz LTE system bandwidth BW divided into 50 physical resourceblocks (PRB #00, PRB #01, . . . , PRB #49) which are grouped into 17resource block groups (RBG #00, RBG #01, . . . , RBG #16) and also howthe predefined initial (unshifted) locations for the 8 narrowbands(INarrowband #00, INarrowband #01, . . . , INarrowband #07) supportedfor this system bandwidth in LTE are arranged in frequency. As indicatedby the legend, the unshifted locations for the narrowbands are shown inthe bottom row of blocks in FIG. 7 (these unshifted locations correspondwith the narrowband locations represented in FIG. 5 ). However, alsoshown in FIG. 7 are shifted locations for the narrowbands (labelled hereas SNarrowband #00, SNarrowband #01, . . . , SNarrowband #07) inaccordance with one example implementation of an embodiment of thedisclosure. In particular, for this example the narrowbands are allshifted from their predefined initial locations by one PRB towards lowerfrequencies (i.e. to the left in FIG. 7 , as shown by the arrow in thelower left of the figure). As indicated by the legend, the shiftedlocations for the narrowbands are shown in the second from bottom row ofblocks in FIG. 7 (i.e. directly below the row representing the resourceblock groups). Thus, as can be seen in FIG. 7 , the single PRB shiftresults in the boundaries for the narrowbands aligning with theboundaries between resource blocks groups, the effect of which is thateach shifted narrowband is formed of physical resource blocks from asmaller number of resource block groups than the correspondingunshifted/initial narrowbands. For example, whereas the unshiftednarrowband INarrowand#03 is on six physical resource blocks (PRB #19 toPRB #24) spread across three resource block groups (RBG #06 to RBG #08),the shifted narrowband SNarrowand#03 is on six physical resource blocks(PRB #18 to PRB #23) spread across only two resource block groups (RBG#06 and RBG #07), thereby avoiding the “blocked” physical resourceblocks discussed above with reference to FIG. 5 when the thirdnarrowband is scheduled and the surrounding narrowbands are notscheduled. It will be appreciated that while FIG. 7 shows one exampleapplication of a common frequency shift (one PRB to the left/lowerfrequency), different shifts may be used in different implementations.Different system bandwidths could also use shifts of different numbersof PRBs.

In some embodiments, an indicated frequency shift may be applicable toonly a subset of the narrowbands (this subset may contain only onenarrowband). This approach may be useful for a system bandwidth that hasa PRB in the middle of the system bandwidth that is not allocated tosupport any of the narrowbands (e.g. in the case of a system bandwidthhaving an odd number of PRBs in an LTE context, such as shown in FIG. 2). Applying different shifts to different subsets of narrowbands allowsmore flexibility. An example is shown in FIG. 8 .

FIG. 8 is in general similar to, and will be understood from, FIG. 7 ,but shows an example implementation for a 3 MHz LTE bandwidth BW (as inFIG. 2 ), rather than the 10 MHz LTE bandwidth example of FIG. 7 . ThusFIG. 8 shows a 3 MHz LTE system bandwidth BW divided into 15 physicalresource blocks (PRB #00, PRB #01, . . . , PRB #14) which are groupedinto 8 resource block groups (RBG #00, RBG #01, . . . , RBG #07). Asindicated in Table 1, the RBG size for a 3 MHz channel bandwidth in LTEis 2 PRB, and so there are 7 RBGs comprising 2PRBs with the last PRBforming its own RBG. FIG. 8 also shows how the predefined initial(unshifted) locations for the 2 narrowbands (INarrowband #00 andINarrowband #01) supported for this system bandwidth in LTE are arrangedin frequency. As indicated by the legend, the unshifted locations forthe narrowbands are shown in the bottom row of blocks in FIG. 8 (theseunshifted locations correspond with the narrowband locations representedin FIG. 2 ). Also shown in FIG. 8 are shifted locations for thenarrowbands (labelled here as SNarrowband #00 and SNarrowband #01) inaccordance with one example implementation of an embodiment of thedisclosure. In particular, for this example the lower frequencynarrowband (left-most in the figure) is shifted by one PRB to theleft/lower frequency (as shown by the arrow in the lower left of thefigure) whereas the upper frequency narrowband (right-most in thefigure) is not shifted (i.e. it is in effect shifted by zero PRBs, asshown by the arrow in the lower middle of the figure). As can be seen inFIG. 8 , these shifts again result in the boundaries for the narrowbandsaligning with the boundaries between resource blocks groups, the effectof which is that each shifted narrowband is formed of physical resourceblocks from a smaller number of resource block groups than thecorresponding unshifted/initial narrowbands. For example, whereas theunshifted narrowband INarrowand#00 is on six physical resource blocks(PRB #01 to PRB #06) spread across four resource block groups (RBG #00to RBG #03), the shifted narrowband SNarrowand#03 is on six physicalresource blocks (PRB #00 to PRB #05) spread across only three resourceblock groups (RBG #00 to RBG #02), thereby avoiding the “blocked”physical resource blocks effect discussed above.

The approach of FIG. 8 may thus be seen as applying different shifts todifferent groups/subsets of narrow bands. In this example there are twogroups defined where Group 1 consists of Narrowband #00 and Group 2consists of Narrowband #01. Group 1 is shifted by 1 PRB to the leftwhilst Group 2 is not shifted. This maintains the PRB gap in the middleof the system bandwidth while at the same time aligns the narrowband andthe RBGs as discussed above. It will be appreciated it is not necessaryto maintain a gap in the middle of the system bandwidth, as is done forthe Example of FIG. 8 , and an example where a gap is not maintained isshown in FIG. 9 .

FIG. 9 is similar to, and will be understood from, FIG. 8 , but shows anexample implementation with a different frequency shift pattern for a 3MHz LTE bandwidth. Thus FIG. 9 again shows a 3 MHz LTE system bandwidthBW divided into 15 physical resource blocks (PRB #00, PRB #01, . . . ,PRB #14) which are grouped into 8 resource block groups (RBG #00, RBG#01, . . . , RBG #07). FIG. 9 again shows how the predefined initial(unshifted) locations for the 2 narrowbands (INarrowband #00 andINarrowband #01) supported for this system bandwidth in LTE are arrangedin frequency. As indicated by the legend, the unshifted locations forthe narrowbands are shown in the bottom row of blocks in FIG. 9 . Alsoshown in FIG. 9 are shifted locations for the narrowbands (labelled hereas SNarrowband #00 and SNarrowband #01) in accordance with one exampleimplementation of an embodiment of the disclosure. In particular, forthis example both narrowbands are shifted from their predefined initiallocations in the same direction (in this case to the left/lowerfrequency), but the lower frequency narrowband is shifted by one PRB (asshown by the arrow in the lower left of the figure) whereas the upperfrequency narrowband is shifted by two PRBs (as shown by the arrow inthe lower middle of the figure). While this shift of the upper frequencynarrowband by two PRBs does not, in this example, alter its relativealignment with the RBGs, it may nonetheless be desired for otherreasons, for example to remove/reduce the gap between the narrowbands toincrease the number of contiguous PRBs not used for narrowbandoperation.

The approach of FIG. 9 may thus again be seen as applying differentshifts to different groups/subsets of narrow bands. In this examplethere are two groups defined where Group 1 consists of Narrowband #00and Group 2 consists of Narrowband #01. Group 1 is shifted by 1 PRB tothe left whilst Group 2 is shifted by 2 PRB to the left.

In some embodiments there may be a number of predefined frequency shiftarrangements that can be indicated using an index for a predefinedlookup table (e.g. defined by an operating standard of the system). Thusa network infrastructure equipment (eNB/base station) need only indicatethe index to the lookup table in the signalling of the frequency shiftconfiguration setting to the terminal device(s). An example lookup tableis shown in Table 2 which has a single shift pattern defined for eachsystem bandwidth. It will be appreciated that other combinations ofshift pattern can be used, for example there can be more than one shiftpattern per system bandwidth.

TABLE 2 System Bandwidth Index MHz (#PRB) Shift Pattern 0 1.4 MHz (6PRB) No shift 1 3 MHz (15 PRB) Shift Narrowband#00 1 PRB to the left &do not shift Narrowband#01 2 5 MHz (25 PRB) Shift Narrowband#02 &Narrowband#03 1 PRB to the left 3 10 MHz (50 PRB) Shift all narrowbands1 PRB to the left 4 15 MHz (75 PRB) Shift Narrowbands#00 tillNarrowbands#05 1 PRB to the left & shift Narrowbands#06 tillNarrowband#11 2 PRBs to the left 5 20 MHz (100 PRB) No Shift

In an example where a lookup table for the shift pattern is used andeach system bandwidth is mapped to one shift pattern, the networkinfrastructure equipment could instead simply signal a single bitindication to indicate whether shifting is applied or not, and the UEcan derive the pattern to apply from the table (having determined thesystem bandwidth separately, e.g. from master information block, MIB,signalling in an LTE context.

In some cases a frequency shift/frequency shift pattern may be signalledto a UE in accordance with the principles described above, and then aseparate indication may be provided to the UE to indicate whether or notto apply the previously indicated shift in respect of individualresource allocations, for example by an indicator in downlink controlinformation, DCI, signalling carrying a downlink or uplink grant to theUE. That is to say, the shift in narrowband(s) may be dynamicallyindicated to the UE. This may in some cases be helpful in a system thatsupports both narrowband devices that can support frequency shifting asdiscussed herein and narrowband devices that cannot support frequencyshifting as discussed herein. Thus when multiplexing both types ofnarrowband device (i.e. frequency-shift-supporting devices andnon-frequency-shift-supporting devices) in a subframe on the samenarrowband, the frequency shifting can be deactivated, and whenmultiplexing shift-capable narrowband devices and full bandwidth legacydevices at the same time the frequency shifting can be activated.Furthermore, this approach can allow for shift patterns in whichdifferent narrowbands overlap in their shifted locations, and ifnarrowbands that overlap in their shifted positons are to be scheduledfor active use at the same time, the scheduling signalling (DCI) canindicate the shift is applied for one narrowband but not another toavoid the overlap when the narrowbands are active at the same time. Forexample, in an example similar to that shown in FIG. 9 , the left-handnarrowband could be shifted one PRB to the right (rather than to theleft as in FIG. 9 ), and the right-hand narrowband could be shifted twoPRBs to the left (as in FIG. 9 ) resulting in these two shiftednarrowbands overlapping in PRB #06 and PRB #07. However, since the shiftcan be applied dynamically, e.g. using DCI, the eNB can indicate a shiftfor one narrowband and not the other when both are scheduled for use atthe same time. In some examples the DCI may indicate the shift withoutprior RRC configuration of the shift pattern. That is to say the DCI maytell the UE which direction and by how many PRBs to shift the narrowbandfor the corresponding allocation. In some examples the DCI may contain 1bit that can be set as a flag to indicate whether to shift the schedulednarrowband such that it aligns to the nearest RBG or to align to alegacy MTC narrowband location (i.e. not perform any shift to thenarrowband). An example of overlapping shifted narrowbands is shown inFIG. 10 .

FIG. 10 is similar to, and will be understood from, FIG. 8 , but showsan example implementation with an overlapping frequency shift patternfor a 20 MHz LTE bandwidth. Thus FIG. 10 shows a 20 MHz LTE systembandwidth BW divided into 100 physical resource blocks (PRB #00, PRB#01, . . . , PRB #99) which are grouped into 25 resource block groups(RBG #00, RBG #01, . . . , RBG #24). FIG. 10 also shows how thepredefined initial (unshifted) locations for four of the sixteennarrowbands (labelled INarrowband #00 to INarrowband #03) supported forthis system bandwidth in LTE are arranged in frequency. As indicated bythe legend, the unshifted locations for the narrowbands are shown in thebottom row of blocks in FIG. 10 . Also shown in FIG. 8 are shiftedlocations for these four narrowbands (labelled here as SNarrowband #00to SNarrowband #03) in accordance with one example implementation of anembodiment of the disclosure. In particular, for this example the lowerfrequency narrowband (left-most in the figure) is shifted by two PRBs tothe left/lower frequency. The next lowest frequency narrowband (nextleft-most in the figure) is shifted by four PRBs to the left/lowerfrequency. The next narrowband is shifted by 6 PRBs, the next by 8 PRBs,and so on. To avoid using overlapping narrowbands at the same time, thenetwork can dynamically indicate whether to apply the shift, e.g. inDCI, for each resource allocation.

In some examples, during a random access procedure, unshiftednarrowbands may be used. This can in some cases be helpful if during theinitial stages of the random access procedure, the eNB does not know thecapability of the UE (e.g. whether it implements the narrowband shiftingfeature or not). Hence during the random access procedure, until the UEtransmits its capability to the eNB to indicate it can operate usingshifted frequencies, unshifted narrowbands may be used. After the randomaccess procedure when the eNB (network infrastructure equipment) isaware the UE supports the feature, narrowband shifting may be employedaccording to whether narrowband shifting is activated or not in eitherSIB signalling or UE-specific RRC signalling.

In some cases, the PRACH (physical random access channel) preamble space(i.e. the set of available PRACH preambles) may be partitioned. Onepartition (partition 1) may be used for UEs that are capable of applyingnarrowband shifting and another partition (partition 2) may be reservedfor UEs that are not capable of applying narrowband shifting. The PRACHpartitions may, for example, be defined by an operating standard orsignalled via SIB. A UE that is capable of narrowband shifting thus usesa PRACH preamble from partition 1 and then decodes a response (e.g. RARin an LTE context) that can be narrowband shifted in accordance with theprinciples described herein.

FIG. 11 is a flow diagram schematically representing a method ofoperating a terminal device to communicate with a network infrastructureequipment in a wireless telecommunications system using radio resourcescomprising a narrowband carrier supported within a wider systemfrequency bandwidth of the wireless telecommunications system inaccordance with the principles discussed herein. In a first step S1 ofthe process represented in FIG. 11 the terminal device establishesinitial frequencies for radio resources comprising the narrowbandcarrier. In a second step S2 of the process represented in FIG. 11 theterminal device receives configuration signalling from the networkinfrastructure equipment providing an indication of a frequency shift toapply to the initial frequencies for the radio resources comprising thenarrowband carrier. In a third step S3 of the process represented inFIG. 11 the terminal device establishes shifted frequencies for theradio resources comprising the narrowband carrier by applying theindicated frequency shift to the initial frequencies. In a fourth stepS4 of the process represented in FIG. 11 the terminal devicecommunicates with the network infrastructure equipment using the radioresources for the narrowband carrier with the shifted frequencies.

FIG. 12 is a flow diagram schematically representing a method ofoperating a network infrastructure equipment (base station) tocommunicate with a terminal device in a wireless telecommunicationssystem using radio resources comprising a narrowband carrier supportedwithin a wider system frequency bandwidth of the wirelesstelecommunications system in accordance with the principles discussedherein. In a first step T1 of the process represented in FIG. 12 thenetwork infrastructure equipment establishes initial frequencies forradio resources comprising the narrowband carrier. In a second step T2of the process represented in FIG. 12 the network infrastructureequipment establishes shifted frequencies for the radio resourcescomprising the narrowband carrier by applying a frequency shift to theinitial frequencies. In a third step T3 of the process represented inFIG. 12 the network infrastructure equipment transmits configurationsignalling to the terminal device to provide an indication of thefrequency shift. In a fourth step T4 of the process represented in FIG.12 the network infrastructure equipment communicates with the terminaldevice using the radio resources for the narrowband carrier with theshifted frequencies.

As discussed herein, the shift may be such that at least one boundary ofone narrowband is shifted into alignment with at least one boundarybetween two RBGs, and more generally, the shift may be such that theradio resources (PRBs) for at least one narrowband carrier span asmaller number of the predefined groups of physical resource blocks(RBGs) for the shifted frequencies than for the initial frequencies.That is to say, the shift may be such that use of the narrowband carrier“blocks” fewer RBGs for its frequency shifted location than for itsnominal predefined (initial) location before shifting.

There are various ways in which the various frequency shifts discussedherein may be communicated to terminal devices. For example, in oneapproach an indication of shifts in both magnitude and direction may beprovided for each narrowband. However, in other examples the indicationof the frequency shift may comprise only an indication of a commonmagnitude which the terminal device is configured to apply to allnarrowbands, with the direction of the shifts being dependent on theinitial predefined location of the narrowband within the systembandwidth, and for example depending on whether the narrowband is in theupper or lower half of the system bandwidth. More generally, for all theexamples described herein there are various different ways in which thedirection and magnitude of the shift of the different narrowband can beindicated in signalling from the network infrastructure equipment to theterminal device and the most appropriate way may depend on the shiftsbeing indicated. For example, if the shifts are the same for allnarrowbands, it may be most efficient for the indication to comprise asingle value/direction that the terminal device is configured to applyfor all narrowbands, whereas if the shifts are different for differentnarrowbands/groups of narrowband, the indication may comprise multiplefrequency shift values/directions that the terminal device is configuredto apply for the corresponding narrowbands. In examples where thepotential frequency shifts are limited to a number of predefinedalternatives, the indication may comprise an index pointing to therelevant shift pattern, e.g. in the manner of a lookup table. Indeed, insome examples the direction and magnitude of the shift of the differentnarrowbands may be defined in an operating standard of the wirelesstelecommunications system, and the signalling indicating the frequencyshift may simply comprise an indication of whether or not to apply thefrequency shift.

Thus there has been described a method of operating a terminal device tocommunicate with a network infrastructure equipment in a wirelesstelecommunications system using radio resources comprising a narrowbandcarrier supported within a wider system frequency bandwidth of thewireless telecommunications system, wherein the method comprises:establishing initial frequencies for radio resources comprising thenarrowband carrier; receiving configuration signalling from the networkinfrastructure equipment providing an indication of a frequency shift toapply to the initial frequencies for the radio resources comprising thenarrowband carrier; establishing shifted frequencies for the radioresources for the narrowband carrier by applying the indicated frequencyshift to the initial frequencies; and communicating with the networkinfrastructure equipment using the shifted frequencies for the radioresources for the narrowband carrier. A terminal device and circuitryconfigured to implement this method have also been described.

There has also been described a method of operating a networkinfrastructure equipment to communicate with a terminal device in awireless telecommunications system using radio resources comprising anarrowband carrier supported within a wider system frequency bandwidthof the wireless telecommunications system, wherein the method comprises:establishing initial frequencies for radio resources comprising thenarrowband carrier; establishing shifted frequencies for the radioresources comprising the narrowband carrier by applying a frequencyshift to the initial frequencies; transmitting configuration signallingto the terminal device to provide an indication of the frequency shift;and communicating with the terminal device using the radio resources forthe narrowband carrier with the shifted frequencies. A networkinfrastructure equipment and circuitry configured to implement thismethod have also been described.

It will be appreciated that while the present disclosure has in somerespects focused on implementations in an LTE-based and/or 5G networkfor the sake of providing specific examples, the same principles can beapplied to other wireless telecommunications systems. Thus, even thoughthe terminology used herein is generally the same or similar to that ofthe LTE and 5G standards, the teachings are not limited to the presentversions of LTE and 5G and could apply equally to any appropriatearrangement not based on LTE or 5G and/or compliant with any otherfuture version of an LTE, 5G or other standard.

It may be noted various example approaches discussed herein may rely oninformation which is predetermined/predefined in the sense of beingknown by both the base station and the terminal device. It will beappreciated such predetermined/predefined information may in general beestablished, for example, by definition in an operating standard for thewireless telecommunication system, or in previously exchanged signallingbetween the base station and terminal devices, for example in systeminformation signalling, or in association with radio resource controlsetup signalling, or in information stored on a SIM card. That is tosay, the specific manner in which the relevant predefined information isestablished and shared between the various elements of the wirelesstelecommunications system is not of primary significance to theprinciples of operation described herein. It may further be notedvarious example approaches discussed herein rely on information which isexchanged/communicated between various elements of the wirelesstelecommunications system and it will be appreciated such communicationsmay in general be made in accordance with conventional techniques, forexample in terms of specific signalling protocols and the type ofcommunication channel used, unless the context demands otherwise. Thatis to say, the specific manner in which the relevant information isexchanged between the various elements of the wirelesstelecommunications system is not of primary significance to theprinciples of operation described herein.

It will be appreciated that the principles described herein are notapplicable only to certain types of terminal device, but can be appliedmore generally in respect of any types of terminal device, for examplethe approaches are not limited to machine type communication devices/IoTdevices, but can be applied more generally, for example in respect ofany type terminal device operating on a narrowband within abroader/wider system bandwidth.

Further particular and preferred aspects of the present invention areset out in the accompanying independent and dependent claims. It will beappreciated that features of the dependent claims may be combined withfeatures of the independent claims in combinations other than thoseexplicitly set out in the claims.

Thus, the foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. As will be understood by thoseskilled in the art, the present invention may be embodied in otherspecific forms without departing from the spirit or essentialcharacteristics thereof. Accordingly, the disclosure of the presentinvention is intended to be illustrative, but not limiting of the scopeof the invention, as well as other claims. The disclosure, including anyreadily discernible variants of the teachings herein, define, in part,the scope of the foregoing claim terminology such that no inventivesubject matter is dedicated to the public.

Respective features of the present disclosure are defined by thefollowing numbered paragraphs:

Paragraph 1. A method of operating a terminal device to communicate witha network infrastructure equipment in a wireless telecommunicationssystem using radio resources comprising a narrowband carrier supportedwithin a wider system frequency bandwidth of the wirelesstelecommunications system, wherein the method comprises: establishinginitial frequencies for radio resources comprising the narrowbandcarrier; receiving configuration signalling from the networkinfrastructure equipment providing an indication of a frequency shift toapply to the initial frequencies for the radio resources comprising thenarrowband carrier; establishing shifted frequencies for the radioresources comprising the narrowband carrier by applying the indicatedfrequency shift to the initial frequencies; and communicating with thenetwork infrastructure equipment using the radio resources for thenarrowband carrier with the shifted frequencies.

Paragraph 2. The method of paragraph 1, wherein the indication of thefrequency shift to apply to the initial frequencies comprises anindication of a magnitude and/or direction of the frequency shift.

Paragraph 3. The method of paragraph 2, wherein the indication of thefrequency shift to apply to the initial frequencies comprises anindication of a magnitude of the frequency shift and the method furthercomprises determining a direction for the frequency shift based on alocation of the initial frequencies within the system frequencybandwidth.

Paragraph 4. The method of any of paragraphs 1 to 3, wherein theindication of the frequency shift to apply to the initial frequenciescomprises an indication of whether or not to apply a predefinedfrequency shift to the initial frequencies.

Paragraph 5. The method of any of paragraphs 1 to 4, wherein theterminal device determines a magnitude and/or direction of the frequencyshift from the indication of a frequency shift in the configurationsignalling by taking account of a magnitude for the system frequencybandwidth.

Paragraph 6. The method of any of paragraphs 1 to 5, wherein theindication of whether or not to apply a predefined frequency shift tothe initial frequencies is provided in downlink control information,DCI.

Paragraph 7. The method of any of paragraphs 1 to 6, wherein theindication of the frequency shift comprises an indication of a selectedone of a plurality of predefined potential frequency shifts.

Paragraph 8. The method of any of paragraphs 1 to 7, wherein theindication of the frequency shift is received by the terminal deviceusing radio resource control, RRC, signalling.

Paragraph 9. The method of any of paragraphs 1 to 8, wherein theindication of the frequency shift is received by the terminal device insystem information in a system information block, SIB.

Paragraph 10. The method of any of paragraphs 1 to 8, wherein theindication of the frequency shift is received by the terminal deviceusing terminal device specific signalling.

Paragraph 11. The method of any of paragraphs 1 to 10, wherein thesystem frequency bandwidth of the wireless telecommunications system isdivided into a plurality of predefined groups of physical resourceblocks which are scheduled together for terminal devices using thesystem frequency bandwidth, wherein the frequency shift is such that arelative alignment between the narrowband carrier and the predefinedgroups of physical resources changes so that radio resources for thenarrowband carrier span a smaller number of the predefined groups ofphysical resource blocks for the shifted frequencies than for theinitial frequencies.

Paragraph 12. The method of any of paragraphs 1 to 11, furthercomprising communicating with the network infrastructure equipment usingthe initial frequencies for the radio resources for the narrowbandcarrier to establish a radio connection with the network infrastructureequipment prior to communicating with the network infrastructureequipment using the shifted frequencies for the radio resources for thenarrowband carrier.

13. The method of paragraph 12, wherein the procedure to establish aradio connection with the network infrastructure equipment involves theterminal device transmitting a random access preamble to the networkinfrastructure equipment, and wherein the random access preamble isselected by the terminal device from a subset of available random accesspreambles defined for use by terminal devices to provide the networkinfrastructure equipment with an indication of an ability to communicatewith the network infrastructure equipment using the shifted frequenciesfor the radio resources for the narrowband carrier.

Paragraph 14. The method of any of paragraphs 1 to 13, wherein thenarrowband carrier is one of a plurality of narrowband carrierssupported within the wider system frequency bandwidth of the wirelesstelecommunications system, and wherein the configuration signallingreceived from the network infrastructure equipment provides anindication of a frequency shift for each of the narrowband carriers.

Paragraph 15. The method of paragraph 14, wherein the frequency shifthas the same magnitude for each of the narrowband carriers.

Paragraph 16. The method of paragraph 14, wherein the frequency shiftfor a first group of the narrowband carriers and the frequency shift fora second group of the narrowband carriers have different magnitudes.

Paragraph 17. The method of paragraph 16, wherein a magnitude for thefrequency shift for one of the first and second groups of the narrowbandcarriers is zero.

Paragraph 18. The method of paragraph 14, wherein the frequency shiftfor a first group of the narrowband carriers and the frequency shift fora second group of the narrowband carriers are in different directions.

Paragraph 19. The method of any of paragraphs 14 to 18, wherein thefrequency shift for at least two of the narrowbands causes thenarrowbands to overlap in frequency when the frequency shift is applied.

Paragraph 20. A terminal device for communicating with a networkinfrastructure equipment in a wireless telecommunications system usingradio resources comprising a narrowband carrier supported within a widersystem frequency bandwidth of the wireless telecommunications system,wherein the terminal device comprises controller circuitry andtransceiver circuitry configured such that the terminal device isoperable to: establish initial frequencies for radio resourcescomprising the narrowband carrier; receive configuration signalling fromthe network infrastructure equipment providing an indication of afrequency shift to apply to the initial frequencies for the radioresources comprising the narrowband carrier; establish shiftedfrequencies for the radio resources comprising the narrowband carrier byapplying the indicated frequency shift to the initial frequencies; andcommunicate with the network infrastructure equipment using the radioresources for the narrowband carrier with the shifted frequencies.

Paragraph 21. Integrated circuitry for a terminal device forcommunicating with a network infrastructure equipment in a wirelesstelecommunications system using radio resources comprising a narrowbandcarrier supported within a wider system frequency bandwidth of thewireless telecommunications system, wherein the integrated circuitrycomprises controller circuitry and transceiver circuitry configured tooperate together such that the terminal device is operable to: establishinitial frequencies for radio resources comprising the narrowbandcarrier; receive configuration signalling from the networkinfrastructure equipment providing an indication of a frequency shift toapply to the initial frequencies for the radio resources comprising thenarrowband carrier; establish shifted frequencies for the radioresources comprising the narrowband carrier by applying the indicatedfrequency shift to the initial frequencies; and communicate with thenetwork infrastructure equipment using the radio resources for thenarrowband carrier with the shifted frequencies.

Paragraph 22. A method of operating a network infrastructure equipmentto communicate with a terminal device in a wireless telecommunicationssystem using radio resources comprising a narrowband carrier supportedwithin a wider system frequency bandwidth of the wirelesstelecommunications system, wherein the method comprises: establishinginitial frequencies for radio resources comprising the narrowbandcarrier; establishing shifted frequencies for the radio resourcescomprising the narrowband carrier by applying a frequency shift to theinitial frequencies; transmitting configuration signalling to theterminal device to provide an indication of the frequency shift; andcommunicating with the terminal device using the radio resources for thenarrowband carrier with the shifted frequencies.

Paragraph 23. A network infrastructure equipment for communicating witha terminal device in a wireless telecommunications system using radioresources comprising a narrowband carrier supported within a widersystem frequency bandwidth of the wireless telecommunications system,wherein the network infrastructure equipment comprises controllercircuitry and transceiver circuitry configured such that the networkinfrastructure equipment is operable to: establish initial frequenciesfor radio resources comprising the narrowband carrier; establish shiftedfrequencies for the radio resources comprising the narrowband carrier byapplying a frequency shift to the initial frequencies; transmitconfiguration signalling to the terminal device to provide an indicationof the frequency shift; and communicate with the terminal device usingthe radio resources for the narrowband carrier with the shiftedfrequencies.

Paragraph 24. Integrated circuitry for a network infrastructureequipment for communicating with a terminal device in a wirelesstelecommunications system using radio resources comprising a narrowbandcarrier supported within a wider system frequency bandwidth of thewireless telecommunications system, wherein the integrated circuitrycomprises controller circuitry and transceiver circuitry configured tooperate together such that the terminal device is operable to: establishinitial frequencies for radio resources comprising the narrowbandcarrier; establish shifted frequencies for the radio resourcescomprising the narrowband carrier by applying a frequency shift to theinitial frequencies; transmit configuration signalling to the terminaldevice to provide an indication of the frequency shift; and communicatewith the terminal device using the radio resources for the narrowbandcarrier with the shifted frequencies.

REFERENCES

[1] RP-161464, “Revised WID for Further Enhanced MTC for LTE”, Ericsson,3GPP TSG RAN Meeting #73, New Orleans, USA, Sep. 19-22, 2016

[2] RP-161901, “Revised work item proposal: Enhancements of NB-IoT”,Huawei, HiSilicon, 3GPP TSG RAN Meeting #73, New Orleans, USA, Sep.19-22, 2016

[3] RP-170732, “New WID on Even further enhanced MTC for LTE”, Ericsson,Qualcomm, 3GPP TSG RAN Meeting #75, Dubrovnik, Croatia, Mar. 6-9, 2017

[4] RP-170852, “New WID on Further NB-IoT enhancements”, Huawei,HiSilicon, Neul, 3GPP TSG RAN Meeting #75, Dubrovnik, Croatia, Mar. 6-9,2017

[5] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based radioaccess”, John Wiley and Sons, 2009

[6] R1-1720541, “On the interest of more flexible resource allocationfor efeMTC”, Orange, 3GPP TSG RAN WG1 Meeting #91, Reno, Nev. USA,November 27-Dec. 1, 2017

1. Integrated circuitry for a terminal device for communicating with anetwork infrastructure equipment in a wireless telecommunications systemusing radio resources comprising a narrowband carrier supported within awider system frequency bandwidth of the wireless telecommunicationssystem, the integrated circuitry comprising: controller circuitry andtransceiver circuitry configured to operate together to: establishinitial frequencies for radio resources comprising the narrowbandcarrier; receive configuration signalling from the networkinfrastructure equipment providing an indication of a frequency shift toapply to the initial frequencies for the radio resources comprising thenarrowband carrier; establish shifted frequencies for the radioresources comprising the narrowband carrier by applying the indicatedfrequency shift to the initial frequencies; and communicate with thenetwork infrastructure equipment using the radio resources for thenarrowband carrier with the shifted frequencies.
 2. The integratedcircuitry of claim 1, wherein the indication of the frequency shift toapply to the initial frequencies comprises an indication of a magnitudeand/or direction of the frequency shift.
 3. The integrated circuitry ofclaim 2, wherein the indication of the frequency shift to apply to theinitial frequencies comprises an indication of a magnitude of thefrequency shift, and the controller circuitry and the transceivercircuitry are configured to operate together to determine a directionfor the frequency shift based on a location of the initial frequencieswithin the system frequency bandwidth.
 4. The integrated circuitry ofclaim 1, wherein the indication of the frequency shift to apply to theinitial frequencies comprises an indication of whether or not to apply apredefined frequency shift to the initial frequencies.
 5. The integratedcircuitry of claim 1, wherein the terminal device determines a magnitudeand/or direction of the frequency shift from the indication of afrequency shift in the configuration signalling by taking account of amagnitude for the system frequency bandwidth.
 6. The integratedcircuitry of claim 1, wherein the indication of whether or not to applya predefined frequency shift to the initial frequencies is provided indownlink control information, DCI.
 7. The integrated circuitry of claim1, wherein the indication of the frequency shift comprises an indicationof a selected one of a plurality of predefined potential frequencyshifts.
 8. The integrated circuitry of claim 1, wherein the indicationof the frequency shift is received by the terminal device using radioresource control, RRC, signalling.
 9. The integrated circuitry of claim1, wherein the indication of the frequency shift is received by theterminal device in system information in a system information block,SIB.
 10. The integrated circuitry of claim 1, wherein the indication ofthe frequency shift is received by the terminal device using terminaldevice specific signalling.
 11. The integrated circuitry of claim 1,wherein the system frequency bandwidth of the wirelesstelecommunications system is divided into a plurality of predefinedgroups of physical resource blocks which are scheduled together forterminal devices using the system frequency bandwidth, wherein thefrequency shift is such that a relative alignment between the narrowbandcarrier and the predefined groups of physical resources changes so thatradio resources for the narrowband carrier span a smaller number of thepredefined groups of physical resource blocks for the shiftedfrequencies than for the initial frequencies.
 12. The integratedcircuitry of claim 1, wherein the controller circuitry and thetransceiver circuitry are configured to operate together to communicatewith the network infrastructure equipment using the initial frequenciesfor the radio resources for the narrowband carrier to establish a radioconnection with the network infrastructure equipment prior tocommunicating with the network infrastructure equipment using theshifted frequencies for the radio resources for the narrowband carrier.13. The integrated circuitry of claim 12, wherein the procedure toestablish a radio connection with the network infrastructure equipmentinvolves the terminal device transmitting a random access preamble tothe network infrastructure equipment, and wherein the random accesspreamble is selected by the terminal device from a subset of availablerandom access preambles defined for use by terminal devices to providethe network infrastructure equipment with an indication of an ability tocommunicate with the network infrastructure equipment using the shiftedfrequencies for the radio resources for the narrowband carrier.
 14. Theintegrated circuitry of claim 1, wherein the narrowband carrier is oneof a plurality of narrowband carriers supported within the wider systemfrequency bandwidth of the wireless telecommunications system, andwherein the configuration signalling received from the networkinfrastructure equipment provides an indication of a frequency shift foreach of the narrowband carriers.
 15. The integrated circuitry of claim14, wherein the frequency shift has the same magnitude for each of thenarrowband carriers.
 16. The integrated circuitry of claim 14, whereinthe frequency shift for a first group of the narrowband carriers and thefrequency shift for a second group of the narrowband carriers havedifferent magnitudes.
 17. The integrated circuitry of claim 16, whereina magnitude for the frequency shift for one of the first and secondgroups of the narrowband carriers is zero.
 18. The integrated circuitryof claim 14, wherein the frequency shift for a first group of thenarrowband carriers and the frequency shift for a second group of thenarrowband carriers are in different directions.
 19. A method ofoperating a network infrastructure equipment to communicate with aterminal device in a wireless telecommunications system using radioresources comprising a narrowband carrier supported within a widersystem frequency bandwidth of the wireless telecommunications system,the method comprising: establishing initial frequencies for radioresources comprising the narrowband carrier; establishing shiftedfrequencies for the radio resources comprising the narrowband carrier byapplying a frequency shift to the initial frequencies; transmittingconfiguration signalling to the terminal device to provide an indicationof the frequency shift; and communicating with the terminal device usingthe radio resources for the narrowband carrier with the shiftedfrequencies.
 20. Integrated circuitry for a network infrastructureequipment for communicating with a terminal device in a wirelesstelecommunications system using radio resources comprising a narrowbandcarrier supported within a wider system frequency bandwidth of thewireless telecommunications system, the integrated circuitry comprising:controller circuitry and transceiver circuitry configured to operatetogether to: establish initial frequencies for radio resourcescomprising the narrowband carrier; establish shifted frequencies for theradio resources comprising the narrowband carrier by applying afrequency shift to the initial frequencies; transmit configurationsignalling to the terminal device to provide an indication of thefrequency shift; and communicate with the terminal device using theradio resources for the narrowband carrier with the shifted frequencies.